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1.
香港巨牡蛎和长牡蛎幼虫及稚贝的表型性状   总被引:3,自引:0,他引:3  
为了评估香港巨牡蛎和长牡蛎在北方沿海的早期表型性状,于2010年7月,以2009年6月在青岛繁育的两种牡蛎为材料,在大连研究了温度(Mt:(22±1.0)℃及Ht:(28±1.0)℃)、盐度(S20:20±1.0及S30:30±1.0)及中间育成环境(ID:室内及OD:室外)对两种牡蛎幼虫及稚贝表型性状的影响。结果表明:香港巨牡蛎壳宽显著大于长牡蛎(P<0.05),壳高及怀卵量显著小于长牡蛎(P<0.05),壳长、鲜重及壳重两者间无显著差异(P>0.05)。在温度和盐度相同情况下,长牡蛎卵径、受精率、孵化率及D形幼虫均大于香港巨牡蛎;香港巨牡蛎幼虫浮游前期生长较慢,而后快于长牡蛎。两种牡蛎幼虫存活能力在15日龄时高温组>中温组;相同温度下,香港巨牡蛎中盐组>高盐组,长牡蛎高盐组>中盐组。幼虫变态期间,较低的温度延迟了变态时间,降低了变态率,使得两种幼虫变态规格大型化。温度是影响幼虫生长、存活、变态的最主要因素,其次为盐度,交互作用几乎尚未起到作用。中间育成阶段,室外比室内培育效果更好,且香港巨牡蛎稚贝壳高在60日龄以后显著大于长牡蛎(P<0.05),环境是影响稚贝生长的最主要因素;无论室内还是室外两种牡蛎稚贝的存活率均在90%以上,且各实验组间无显著差异(P>0.05)。  相似文献   

2.
在室内实验条件下,研究了体重、饵料密度和质量对太平洋牡蛎同化率的影响.结果表明,太平洋牡蛎的滤水率、摄食率随个体的增大而增加,并且都符合幂函数模式:FR(IR)=aWb.太平洋牡蛎同化率与其个体大小的关系不明显.饵料丰度和质量是影响太平洋牡蛎同化率的重要因素.随食物中有机物含量(POM/TPM)的增加,太平洋牡蛎的同化率也增加,随饵料密度的增加而降低.  相似文献   

3.
盐度对长牡蛎和近江牡蛎及其杂交稚贝生长和存活的影响   总被引:2,自引:0,他引:2  
2011年8月以长牡蛎自繁组GG(Crassostrea gigas♀×C.gigas♂),近江牡蛎自繁组AA(C.ariakensis♀×C.ariakensis♂)、正交组GA(Crassostrea gigas♀×C.ariakensis♂)、反交组AG(C.ariakensis♀×C.gigas♂)为实验材料,开展了稚贝对盐度的适应性研究。结果发现长牡蛎的最适生存盐度为15—35,最适生长盐度为25—35;近江牡蛎的最适生存盐度为10—25,最适生长盐度为20—25;GA的最适生存盐度为15—30,最适生长盐度为15—30,AG的最适生存盐度为20—30,最适生长盐度为20—25。GG对低盐度敏感,AA对高盐度敏感,AG具有高盐度存活的杂种优势,在盐度30时,中亲杂种优势HG×A为13.32,单亲杂种优势HGA和HAG分别为1.89和27.88,在盐度40时,HAG上升到400,GA和AG都不具有生长优势。杂种稚贝对盐度适应介于双亲之间,且表现出一定程度的父系遗传特点。  相似文献   

4.
遗传标记的发展   总被引:18,自引:0,他引:18  
遗传标记 (Genetic Markers)是基因型特殊的易于识别的表现形式。它一般具有较强的多态性、表现的共显性、不影响重要的农艺性状和经济方便、易于观察记载等优点。它在遗传学的建立和发展过程中起着重要作用。随着遗传学的发展 ,遗传标记也在不断的发展。从遗传学的建立到现在 ,遗传标记的发展主要经历了 4个阶段 ,表现出了 4种类型。1 形态标记 (Morphological Markers)形态标记是指生物的外部特征特性。包括质量性状作遗传标记和数量性状作遗传标记 ,例如人的肤色、作物的株高、种子的粒形和动物的体重等。它是最早被使用和研究的一类…  相似文献   

5.
本文介绍了目前在蕈菌研究中的酯酶同工酶标记,RAPD标记,RFLP标记,AFLP标记,简单重复序列标记和电泳核型等分子标记和生化标记在蕈菌遗传育种、菌株鉴定、遗传多样性研究、亲缘关系和基因定位等方面的研究、应用现状,包括原理、应用领域及最新研究进展。  相似文献   

6.
1 引言 柳牡蛎蚧(Lepidosaphes salicina Bersch)(同翅目:盾蚧科)是一种以为害杨树为主的刺吸式害虫之一,广泛分布于“三北”防护林区,该蚧一年发生一代,以卵越冬。通过刺吸式口器刺入树皮内,吸取树木养分和水分,并使树木表皮栓化。同时,由于枝干被蚧壳所覆盖,对呼吸及光合作用也有影响,特别是幼树被害后,一般  相似文献   

7.
目的:研究牡蛎肽对小鼠免疫功能的影响。方法:将牡蛎肽按0.5、1、2g/kgBW配置为不同浓度,ICR雌性小鼠按0.2 mL/10 g BW经口灌胃30d后,测定免疫器官重量、迟发型变态反应(足趾增厚法)、抗体生成细胞、血清溶血素含量,并镜观察胸腺组织形态。结果:牡蛎肽可以增加免疫器官相对重量和血清溶血素含量,并能显著增加抗体生成细胞和迟发型变态反应(P<0.05)。结论:牡蛎肽可在一定程度上增强小鼠免疫功能。  相似文献   

8.
太平洋牡蛎酪氨酸酶基因家族的系统发生分析   总被引:1,自引:0,他引:1  
于雪  于红  孔令锋  李琪 《遗传》2014,36(2):135-144
文章利用生物信息学方法对太平洋牡蛎(Crassostrea gigas Thunberg)酪氨酸酶基因家族的氨基酸序列特征、分类及系统发生进行了分析。结果表明, 太平洋牡蛎酪氨酸酶基因家族在进化过程中存在基因扩张现象, 其主要方式是基因重复。太平洋牡蛎酪氨酸酶可分为3种类型:分泌型 (Type A), 胞内型 (Type B)和具跨膜结构域型 (Type C)。根据太平洋牡蛎酪氨酸酶进化树分析, 发现Type A酪氨酸酶中, tyr18与其他Type A酪氨酸酶分化较大, 可能是较早分化出来的酪氨酸酶; Type B酪氨酸中的tyr2和tyr9以及Type C中的tyr8为较早分化出的酪氨酸酶。系统发生树分析发现太平洋牡蛎酪氨酸酶的聚类受酪氨酸酶类型以及基因位置的影响, 其分泌型酪氨酸酶首先与头足类分泌型酪氨酸酶聚在一起, 然后与线形动物门分泌型酪氨酸酶聚在一起, 与腔肠动物门分泌型酪氨酸酶分化明显。太平洋牡蛎胞内型酪氨酸酶自身分化较大, 总体上与线性动物门、其他软体动物胞内型酪氨酸酶聚为一支, 与扁形动物门、脊索动物门、腔肠动物门胞内型酪氨酸酶分化较大。太平洋牡蛎具跨膜结构域型酪氨酸酶与扁形动物门、环形动物门以及脊索动物门具跨膜结构域型酪氨酸酶分化明显, 与合浦珠母贝具跨膜结构域型酪氨酸酶聚为一支。这表明双壳类的Type C型酪氨酸酶与其他物种的同源酶的进化差异较大。文章首次探讨了太平洋牡蛎酪氨酸酶家族分类、分化及系统发生, 以期对太平洋牡蛎酪氨酸酶基因家族的理论研究和实际应用提供依据。  相似文献   

9.
太平洋牡蛎同化率的研究   总被引:7,自引:0,他引:7  
在室内实验条件下,研究了体重、饵料密度和质量对太平洋特蛎同化率的影响。结果表明,太平洋牡蛎的滤水率、摄食率随个体的增大而增加,并且都符合幂函数模式:FR(IR)αW^b。太平洋牡蛎同化率与其个体大小的关系不明显。饵丰度和质量是影响太平洋牡蛎同化率的重要因素,随食物中有机和的含量(POM/TPM)的啬太平洋牡蛎的同化率也增加,随铒料密度的增加而降低。  相似文献   

10.
姜璐  余静 《生态学报》2021,41(18):7484-7491
牡蛎礁作为重要的海岸带生态系统,具备水质净化、提供栖息地等多种生态系统服务功能。为了解国内外牡蛎礁研究的现状与热点,分别以Web of Science 核心合集数据库和中国期刊全文数据库为数据源,通过国内外发文趋势分析、高频关键词分析、关键词共现和聚类分析及主题时间演变分析等,分析牡蛎礁研究热点与趋势。研究结果表明:(1)国际与国内牡蛎礁研究发文量总体呈现上升趋势,但国内研究增长速率低于国际研究;(2)牡蛎礁生态恢复研究是国内外研究的共同关注点,但国内相关研究起步较晚;(3)以外,国际上对牡蛎礁的研究更加关注生态系统服务功能、气候变化等,而国内主要倾向于从地质学角度进行研究;(4)近年来,气候变化成为国际牡蛎礁研究新的热点,但国内对此关注较少。本研究将为了解当前国内外牡蛎礁研究现状及发展态势提供借鉴,并为我国牡蛎礁保护与修复方面的政策制定、科学研究等工作的开展提供情报参考。  相似文献   

11.
Samuli Lehtonen   《Aquatic Botany》2009,91(4):279-290
The phylogenetic relationships of aquatic plant families Alismataceae and Limnocharitaceae were investigated by cladistic analysis of morphological and cytological characters. The use of morphological data allowed much wider taxon sampling than in recent molecular studies, and resulted in several new hypotheses. Limnocharitaceae was resolved as a paraphyletic group giving rise to the monophyletic Alismataceae, contradicting with the results from molecular studies. Most of the currently accepted genera were relatively well supported as monophyletic groups, with polyphyletic Caldesia and paraphyletic Limnophyton as notable exceptions. Phylogenetic relationships between different genera remained poorly supported, but it is suggested that the base chromosome number n = 11 is derived from the plesiomorphic n = 7.  相似文献   

12.
苔藓植物分子系统学研究概况   总被引:1,自引:0,他引:1  
李晶  沙伟 《植物学通报》2004,21(2):172-179
结合同工酶分析技术及随机扩增多态性DNA(RAPD)、限制性片段长度多态性(RFLP)和DNA序列测序3种分子生物学技术,对苔藓植物的分子系统学研究概况进行了介绍,并指出了在苔藓植物分子系统学研究中存在的一些问题.  相似文献   

13.
Morphological markers as well as two types of molecular markers, inter-sample sequence repeat (ISSR) and start codon targeted (SCoT) are suitable for species identification of the polygonati rhizoma germplasms. In this paper, we adopted these methods for the identification of rhizomes collected from 47 areas in China. Based on their morphological characters, the collected germplasms were classified into two populations, one with alternate leaf arrangement and the other with verticillate leaf arrangement, and they were comprised of five species and fourteen subgroups. Of the five species identified: Polygonatum kingianum, P. cirrhifolium, P. alternicirrhosum, and P. sibiricum belonged to one cluster, and P. cyrtonema belonged to a different cluster. According to the analysis of both ISSR and SCoT markers, all germplasms with greater genetic similarity were classified into one group. Especially, P. sibiricum and P. cirrhifolium, which shared ~80% similarity, were clustered together, whereas the germplasms identified as P. kingianum with ~86% similarity formed a separate clade. P. kingianum showed a much greater genetic similarity with P. cyrtonema than with P. sibiricum. The multidimensional scaling analysis further verified the accuracy and reliability of the molecular marker-based results. Thus, both morphological and molecular methods should be combined for the differentiation of germplasms such as those of polygonati rhizoma.  相似文献   

14.
Patterns of diversification in species-rich clades provide insight into the processes that generate biological diversity. We tested different models of lineage and phenotypic diversification in an exceptional continental radiation, the ovenbird family Furnariidae, using the most complete species-level phylogenetic hypothesis produced to date for a major avian clade (97% of 293 species). We found that the Furnariidae exhibit nearly constant rates of lineage accumulation but show evidence of constrained morphological evolution. This pattern of sustained high rates of speciation despite limitations on phenotypic evolution contrasts with the results of most previous studies of evolutionary radiations, which have found a pattern of decelerating diversity-dependent lineage accumulation coupled with decelerating or constrained phenotypic evolution. Our results suggest that lineage accumulation in tropical continental radiations may not be as limited by ecological opportunities as in temperate or island radiations. More studies examining patterns of both lineage and phenotypic diversification are needed to understand the often complex tempo and mode of evolutionary radiations on continents.  相似文献   

15.
The Caribbean Islands are one of the ten insular biodiversity hotspots that are defined based on endemicity, massive habitat loss and vulnerability to extinction. Asteraceae genera endemic to islands have provided well known examples of plant radiation worldwide and illustrate the importance of these insular systems for evolutionary and conservation studies. A review of known patterns of taxonomic diversity and molecular cladistics is provided for Asteraceae genera and species endemic in the Caribbean Island biodiversity hotspot. We found that when compared with other island systems worldwide the Caribbean Islands have the highest number of endemic genera (41), have endemic genera in the highest number of tribes, and harbor the only Asteraceae tribe endemic to an island system, the Feddeeae which is restricted to Cuba. These unique patterns identify the Caribbean Islands as the most important insular area of endemism for this major plant family. Molecular cladistic studies are limited to only seven species in seven endemic genera and six endemic species in five non-endemic genera. These few studies are however relevant as: (1) they confirm the tribal status of the Feddeeae, (2) suggest colonization events from the highlands of Cuba toward low elevation and geologically recent areas of the Bahamas and South Florida, (3) provide evidence for biogeographical links to remote regions of the Pacific Basin, and (4) identify sister relationships with continental taxa, mostly from North America.
Resumen  Las Islas del Caribe son uno de los diez “punto calientes” insulares de biodiversidad, los cuales vienen definidos por sus niveles de endemicidad, masiva pérdida de habitat y vulnerabilidad y extinción. Asteráceas endémicas de islas han proporcionado ejemplos muy bien conocidos de radiación vegetal a nivel mundial, éstos ilustran la importancia de los sistemas insulares en estudios evolutivos y de conservación. Se presenta una revisión de las pautas de diversidad taxonómica y de cladismo molecular en Asteráceas de las Islas del Caribe. Hemos encontrado que comparadas con otros sistemas insulares, las Islas del Caribe tienen el mayor número de géneros endémicos (41), tienen géneros endémicos en el mayor número de tribus y poseen la única tribu de la familia endémica en islas, Feddeeae es endémica de Cuba. Estas pautas de diversidad exclusivas de las Islas del Caribe hacen que éstas sean el área de endemismos insulares más importante para las Asteráceas. Estudios de cladismo molecular se limitan solamente a siete especies en siete géneros endémicos y a seis especies en cinco géneros no endémicos. Este reducido número de estudios son de todas formas relevantes debido a que: (1) confirman el estatus a nivel de tribu de Feddeeae, (2) sugieren una ruta de colonización desde zonas altas de Cuba hacia áreas de baja elevación de las Bahamas y el sur de la Florida, (3) proporcionan evidencia de conexiones biogeográficas con regions remotas del Océano Pacífico, y (4) identifican relaciones de hermandad con táxones continentales, principalmente de América del Norte.
  相似文献   

16.
广东中部两种常见灌木的生态学比较   总被引:8,自引:0,他引:8       下载免费PDF全文
 通过对广东中部的阳生性灌木桃金娘和阴生性灌木九节的形态学、解剖学、植物生态学以及植物生理学等方面的比较发现:处于强光照下的桃金娘通过大的根系、多的枝叶和小的叶片在水分和养分竞争中处于优势,并利用小的枝角和叶毛来避免强光的伤害,而九节则是通过其叶、枝的最经济数量和最佳位置排列来充分利用阴暗不足的光线;桃金娘通过叶片和栅栏组织厚度以及短的小脉间距在强光下能继续进行光合作用并尽快运出光合产物,而九节的叶片则可充分利用森林底层有限的光照;在南亚热带,30%左右的透光率是林下耐荫性树种九节入侵和阳生性灌木桃金娘消亡的辐射条件;九节的生态对策为K对策,而桃金娘遵循r对策;九节和桃金娘的平均光合速率分别为5.9±1.6μmol CO2·m-2·s-1和11.9±0.4μmol CO2·m-2·s-1,光补偿点分别为0.005和0.012mmol·m-2·s-1,光饱和点分别为0.04和0.39μmol CO2·m-2·s-1,气孔传导率分别为0.053±0.037μmolCO2·m-2·s-1和0.101±0.013 mol·m-2·s-l,暗呼吸速率分别为0.42±0.0lμmol CO2·m-2·s-1和0.16±0.15μmolCO2·m-2·s-1,这些生理学差异、形态解剖学差异等与其生境差异有密切的关系。  相似文献   

17.
18.
A phylogenetic reconstruction of feather mites of the epidermoptid complex (Analgoidea: Epidermoptidae, Dermationidae, and Knemidocoptidae) was carried out by methods of parsimony-based cladistics. The epidermoptid complex splits into two major branches, Epidermoptidae and Dermationidae. The family Dermationidae is monophyletic, while the Epidermoptidae, as previously defined, is paraphyletic. The family Knemidocoptidae is reduced to the subfamilial rank because it arises from the core of the Epidermoptidae. The subfamily Myialginae Trouessart, 1906 stat. resur. is restored within the Epidermoptidae. The aberrant genera Lukoschuscoptes and Apocnemidocoptes are moved from Knemidocoptidae to Epidermoptidae and Dermationidae, respectively. A hypothesis explaining main trends in morphological and ecological adaptations to parasitism on birds within the epidermoptid complex is proposed. New taxonomic diagnoses for higher taxa (families and subfamilies) are provided, and three new genera—Archemyialges gen. n., Hemimyialges gen. n. (Epidermoptidae), and Trochiloptes gen. n. (Dermationidae)—and a new subfamily—Apocnemidocoptinae—are established.  相似文献   

19.
除莠活性链霉菌的系统发育研究及其活性产物分析   总被引:2,自引:0,他引:2  
从云南地区土壤中分离到一株具有除莠活性的放线菌(Actinomycetes),对其产生的活性物质进行了分离、纯化及分析。从该菌株的发酵液中获得了有除莠活性的黄色结晶,薄板层析的结果表明,该结晶为多组分混和物,且每一组分均具有除莠活性。通过红外分析对其组分作了初步鉴定。同时对该菌株进行了形态、化学及系统发育学研究,根据16S rDNA全序列构建了系统发育树,结果表明此菌株应属于链霉菌属(Streptomyces),同时具有耐低温和耐盐的特性。  相似文献   

20.
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